The present invention relates generally to tracking and/or monitoring/verifying access a letter, package, or other movable object, and more particularly to a positioning device, a memory device, a radio frequency transponder and/or a fingerprint scanner embedded in a label or other thin object.
There is a desire on the part of both individuals and corporations to be able to track or locate or verify access/receipt or control access to packages, letters, and other movable objects placed in the stream of commerce, as well as household goods and valuables that become lost or stolen. In many cases, these items tend to have a high dollar and or a high sentimental value, or are extremely time-sensitive. The incidences of lost or misplaced or misdirected cargo can detract significantly from the bottom line of both transportation companies and the uninsured owners of the goods. Keeping track of where a particular package is located is a labor intensive task for the transportation company handling the goods, and the consumer must rely on the shipping company to actively inform him or her of the past whereabouts of the package, which tends to consist of posting the information on the shipper's web site. Usually, the information known to the shipper is restricted to the location where the package handler physically obtained the package and actively identified the package using, for example, an optical scanner. While radio frequency identification has been implemented in an effort to automate the process (i.e. eliminate the human package handler), the basic problem still remains: information cannot be easily obtained concerning the whereabouts of the package between the active identification locations. Because of this, a low cost, uncumbersome, and unobtrusive means is needed to provide accurate tracking information of a package or other moveable object. Still further, it is difficult to quickly and conveniently verify that someone has accessed a package, or that someone should not access a package.
Radio frequency identification systems rely on radio frequency transponders to transfer information to interrogation stations. Unlike other information communication systems, radio frequency transponder systems are not restricted to line of sight or hard wire communications, and are most desirable where wireless communications are a necessity. Information transferred by a radio frequency transponder system typically comprises identification data, but can also include messages, depending on the sophistication of the electronics used in the system.
Radio frequency identification systems include an interrogator, which typically employ an exciter that transmits a radio frequency excitation signal, and a transponder. The transponder is energized by the excitation signal to transmit a signal, including an identification code or other information, back to the interrogator. The transponder receives a radio frequency signal, or, more specifically, is energized by the radio frequency magnetic field and forms a response signal that will identify the transponder and which may provide additional information, and then transmits the response signal to the interrogator. The interrogator includes a receiver that receives the response signal and processes the information it contains. This information is then recorded by a data management system for access by the end user.
One method of radio frequency identification works on an inductive principle. Here, an interrogation station generates a magnetic field at a predetermined frequency. When the transponder enters the field, a small electric current forms in the transponder, providing power to the radio frequency identification electronic control components which then modulate the magnetic field in order to transmit the transponder's programmed data back to the interrogator. The interrogator receives the signal transmission, demodulates and decodes the transmission, and sends the data on to a host computer for further processing.
Radio frequency transponders are classified as either passive or active. Passive radio frequency transponders extract their power from the electromagnetic field provided by the interrogator, while an active radio frequency transponder includes a radio transceiver and a battery power source to enable it to transmit a signal to a remote receiver. The advantage to using active transponders is that they typically have increased range over passive transponders, but the disadvantage is that they require a battery power source to achieve that increased range.